Well control



I Fh 1969 W.J. BIELSTEIN ETA-L 7 3 WELL CONTROL Sheet CIRCULATION PORT DEFLATION PORT Filed Nov. 23, 1966 iNFLATlON PORT /FROM BORE mR R05 W II [NVEN1'OR.5. WALTER J. BIELSTEIN, %2111. HARRISON ATTORREY- United States Patent US. Cl. 166-244 Int. Cl. E21b 43/00, 23/06, 21/00 15 Claims The present invention generally concerns method and apparatus for shutting in a well during drilling operations. More particularly, the invention concerns method and apparatus for closing off the annulus between a drill string and borehole wall and conducting operations thereafter in order to remedy blowout or other undesirable well conditions that require correction.

In order to permit remedial action to be taken to control a well in which a blowout has occurred during drilling operations without hazard, the well is desirably shut in at the bottom of the hole. A blowout preventer is used to seal the annulus just above the zone that is providing an influx of fluid (oil, gas or water) caused by the reservoir pressure of that zone being greater than the hydrostatic pressure exerted by the normal circulating drilling fluid. Circulation of fluid above this point allows the well to be controlled without further influx of reservoir fluids and provides several distinct operating advantages. The time for well control is reduced. Also, density of the circulating fluid can be increased to the level require-d to control a high pressure zone with minimnum time and cost. Mud losses and mud costs are reduced because it is not necessary to optimize mud weight while attempting to determine or feeling for a high pore pressure (e.g., 13+pounds/ gallon equivalent) formation in which to set intermediate casing. Other advantages achieved through the ability to circulate above the blowout preventer include desired minimization of surface casing length and thickness and substantial elimination of the previously required intermediate liners; e.g., liners set from 8 to 12 thousand feet. Further, faster drilling results from lowered mud weight and improved hydraulics and elimination of deliberate drilling rate slow-down to compensate for gas cutting of the mud or for potential hazard of crossing poorly defined pressure sealing faults. When the blowout preventer is released, normal circulation and operations can be restored using a heavier circulating fluid. The same circulation procedure can be used to allow time for healing a lost returns zone by keeping a heavy fluid from the lost returns zone either above or below the blowout preventer. Variations in the circulation technique will be obvious to those familiar with the art of well control.

A primary object of the present invention is to provide an improved blowout prevention method and apparatus for shutting in a well while conducting drilling operations. Although this invention primarily serves to control blowouts which occur while drilling the borehole, it may also be employed in healing lost returns zones and aiding in overcoming other problems encountered during drilling operations.

In accordance with the teachings of the invention, the apparatus includes an annular, flexible, fluid-expansible sealing means or packer arranged on a tubular member and inserted in a drill string; means are provided for controlling the introduction of fluid into the packer to cause expansion thereof and for controlling removal of the fluid from the packer to permit the packer to contract. In one embodiment of the invention, fluid pressure-operated valves control the introduction and removal of fluid from the packer, while in another embodiment of the invention, fluid movement into and from the packer is controlled by compression and tension of the drill string. The blowout preventer of this invention will normally be positioned just above the drill collars of the drill string. However, it can be located at other points along the drill string. The blowout preventer is capable of sealing the space between the drill string and the well bore either in open hole or in casing. The annulus area below the seal made by the packer will be isolated from the annulus area above such seal. Means are provided in the drill string to permit drilling fluid circulation above the blowout preventer seal. Also in accordance with the teachings of this invention, a method is provided for preventing blowouts in wells during drilling operations in which drilling fluid is circulated down the drill string and up the annulus between the drill string and the borehole wall which comprises the steps of sealing off the annulus between the drill string and the borehole wall; opening a circulation port in said drill string above said sealed-off annulus; and circulating drilling fluid, adjusted to a desired weight, thnough said circulation port to maintain control of the well.

The above object and other objects and advantages of the invention will be apparent from a more detailed description thereof when taken with the drawings wherein:

FIG. 1 is a sectional, elevational view illustrating one embodiment of the present invention;

FIG. 2 is a more detailed view of a portion of the apparat-us shown in FIG. 1, (partly in section;

FIG. 3 is a more detailed view of another part of the apparatus illustrated in FIG. 1, partly in section; and

FIGS. 4 and 4A are elevation views, partly in section, illustrating another embodiment of this invention.

Referring to the drawings, in FIG. 1 is shown a borehole 10 being drilled by a drill bit 11 into a high-pressure formation 12. The upper end of the drill collars 13 attached to drill bit 11 are splined as at 14 to a tubular member or mandrel 15, the upper end of which is connected to the lower end of a drill string 19. An inflatable packer or sealing member 16 is arranged on mandrel 15. A fluid circulation port 1'7 and a packer deflation port 18 are shown located above packer 16.

As seen more clearly in FIG. 2, mandrel is pro vided with a fluid passageway 9 which terminates at its lower end in the interior of packer 16 and at its upper end in the interior of mandrel 15 at port 8. As seen more clearly in FIG. 3, three pressure-actuated valve members 20, 21 and 22, only one of which, valve member 20, is shown in FIG. 2, are arranged in mandrel 15. Valve mem ber is a check valve which includes a movable plug closure member 23 biased by a spring 24 to a seat 25 formed in an enlarged area of conduit 9. Spring 24 is connected at one end to plug 23 and supported at the other end by a stop portion 26 of valve member 20. This valve member is located closest to circulation port 8. Valve member 21, positioned next closest to circulation port 8 in fluid passageway 9, includes a movable plug closure member 30, which initially seats in an enlarged area 34 of passageway 9, and a stop portion 31 to which is connected a shaft 32 secured initially to closure member by means of a shear pin 33. Another passageway 35 terminates in passageway 9 at one end and in deflation port 18 at the other end thereof. Valve member 22 includes a movable plug closure member 36, which initially seats in an enlarged area of passageway 35, attached to a shaft 37 initially secured to a stop portion 38 of valve member 22 by means of a shear pin 39.

Circulation port 17 in drill string 19 fluidly communicates the interior and exterior of the drill string and is provided with a slidable sleeve valve 41 which can be opened and closed by wire line. Such a valve is commercially available and may be of the type illustrated on page 3820 (vol. 3) of the 1966-67 Composite Catalog of Oil Field Equipment and Services.

In the operation of this embodiment of the invention,

when high pressure formation 12 is penetrated by drill bit 11 and it is desired to inflate packer 16 and close off the annulus 45, drilling is halted and the hydraulic pressure of the drilling fluid, circulated through drill string 19, tubular member 15, drill collars 13 and drill bit 11 and up the annulus 45 between the drilling apparatus and the borehole Wall, is increased to a predetermined pressure; e.g., 800 psi. higher than normal circulation pressure. Valve 41 maintains circulation port 17 closed. This hydraulic pressure acts on movable plug 23 of the pressureoperated check valve through port 8 and conduit 9 against the bias of spring 24 to move plug 23 off seat 25 to open conduit 9 and permit fluid pressure to act on the plug portion of fluid pressure-operated valve 21. Under preferably a further increased hydraulic pressure force, shear pin 33 shears and plug 30 is moved off seat 34 and conduit 9 is opened completely. (Valve 21 is employed as a backup for valve 20. Although preferably included in the valve system, it is not an essential component thereof. Valve 20 may be inadvertently opened in response to pressure surges of the circulating fluid which may occur. In such instances, valve 21 would remain closed and prevent accidental expansion of packer 16.) Fluid pressure then expands packer 16 and seals the annulus 45 between tubular member 15 and the Wall of borehole 10, as illustrated in FIG. 1. Hydraulic pressure within the drill string and tubular member 15 is then decreased and pressure-operated valve 20 closes passageway 9 by movement of plug 23 to seat 25 under the bias of spring 24. Fluid pressure is prevented from escaping from packer 16 and the packer is retained in inflated condition Circulation port 17 is then opened by sliding sleeve 41 from closed position by means of a wire line and drilling fluid is then circulated down drill string 19 through circulation port 17 and up annulus 45 between the drill and the borehole wall. The drilling fluid weight can be adjusted to compensate for drilling through the higher pressure formation while the fluid is circulating or lighter circulating fluid may be employed in the event it is desired to treat a lost returns zone.

When it is desired to deflate packer 16, the circulation port 17 is closed by returning slidable sleeve 41 to its closed position shown in FIG. 2 by means of a wire line and then increasing hydraulic pressure in the drill string and tubular member 15 to a predetermined pressure level; for example, 800 p.s.i. higher than the pressure required to open valves 20 and 21 and inflate packer 16. This increased hydraulic pressure opens valve 20 and acts on plug 36 of valve 22 causing shear pin 39 to shear and moves plug 36 from seat 40 to a position which opens communication between passageways 9 and and deflation port 18. Hydraulic fluid in the annulus surrounding tubular member 15 then forces the fluid contained within packer 16 to flow through passageway 9, passageway 35 and out deflation port 18 into the annulus surrounding tubular member 15. Drilling may then be resumed.

Referring to FIGS. 4 and 4A, an embodiment of the invention is illustrated in which a tubular member 50 on which is arranged an inflatable packer 51 is provided with a passageway 52, which terminates at its lower end in the interior of packer 51 and at its upper end in a chamber 53 formed by tubular member 50 and a lower extension portion 55 of the drill string 56. Extension 55 includes a piston member 57 provided with seals 58 which engage the upper end of the tubular member 50, which forms the outer wall of chamber 53. An upper shoulder stop 59 is formed on tubular member 50 to limit upward movement of piston 57. Lower seals 60 on extension 55 engage the inner wall of chamber 53 formed in tubular member 50. Extension 55 is splined to keyways 61 in the outer wall of chamber 53 by key members 62. Packer inflate fluid 63 is retained in chamber 53.

As similarly described in the previous embodiment, a circulation port 64 provided in drill string 56 above packer 51 is opened and closed by means of a slidable valve sleeve 65 operated by a wire line.

In the operation of the embodiment of FIGS. 4 and 4A, during drilling, packer 51 is maintained in its normal deflated condition by tension in the drill pipe. Packer 51 and tubular member 50 are positioned in the drill string just above the drill collars. When it is desired or becomes necessary to inflate packer 51, drilling is halted and the drill string and extension 55 are placed in compression by setting down weight on drill string 56. Fluid 63 contained in chamber 53 is forced, by piston 57 as the piston moves downwardly, through passageway 52 into the interior of packer 51 to inflate the packer and seal off the annulus between tubular member 50 and the borehole wall. When it is desired to deflate packer 51, weight on drill string 56 is picked up, which raises piston 57 to its initial position adjacent stop 59, and fluid pressure in the annulus between the drill string and the borehole wall contracts packer 51 and forces the fluid 63 back into. the storage chamber 53 through passageway 52.

Circulation port 64 may be used in the same manner that it was used as described with regard to the embodiment of FIGS. 1, 2 and 3; that is, it may be opened by wire line to circulate fluid through the drill string and up the annulus between the drill string and the borehole wall when packer 51 is inflated and may be closed to prevent such circulation as desired.

Packer 51 is commercially available. This flexible seal may be of the type illustrated on page 3090 (vol. 2) of the 196263 Composite Catalog of Oil Field Equipment and Services. Such a packer is designed to be set in a cased or open hole well bore.

Various modifications and arrangements may be made in the embodiments of the invention as illustrated and described herein without departing from the spirit and scope of the invention.

Having fully described the objects, advantages, apparatus and operation of our invention, we claim:

1. Apparatus for use in controlling wells during drilling operations in which drilling fluid is circulated down a drill string having a fully open bore therethrough and up the annulus between said drill string and the borehole wall comprising:

a tubular member having a fully open bore therethrough insertable in said drill string;

a fluid inflatable packer arranged on said tubular member adapted, when expanded, to close off the annulus between the drill string and the borehole wall; and

fluid control means connected to said tubular member for controlling introduction of fluid to said packer to inflate said packer and to permit removal of fluid from said packer to permit said packer to deflate;

said fully open bores through said tubular member and said drill string being maintained during all operations of said apparatus.

2. Apparatus as recited in claim 1 in which said fluid control means comprises:

first passageway means adapted to fluidly communicate the interior of said drill string and the interior of said packer;

first fluid pressure-operated valve means arranged in said first passageway;

second passageway means adapted to fluidly communicate the exterior of said drill string and the interior of said packer connected to said first passageway means; and

second fluid pressure-operated valve means arranged in said second passageway.

3. Apparatus as recited in claim 2 in which said first valve means includes means adapted to maintain said first passageway means open when fluid pressure acting on said first valve means is at a first predetermined pressure level and to maintain said first passageway means closed when said fluid pressure is below said first predetermined pressure level; and

said second valve means includes means adapted to open said second fluid passageway means in response to fluid pressure of a second predetermined pressure level higher than said first predetermined pressure level. 4. Apparatus as recited in claim 3 in which said first valve means includes an additional fluid pressure-operated valve means adapted to open said first passageway means in response to fluid pressure between said first and second predetermined pressure levels.

5. Apparatus as recited in claim 1 in which said fluid control means includes a chamber adapted to contain packer inflate fluid; and

piston means arranged on the lower end of said drill string forming the upper end of said chamber adapted to move vertically relative to said tubular member;

said tubular member and said drill string being connected together in a manner such that when said drill string is placed in compression, inflate fluid contained in said chamber is forced by said piston into said packer to inflate said packer and seal off the annulus between said tubular member and the borehole wall and when said drill string is placed in tension, said packer is permitted to deflate and force said inflate fluid into said chamber.

6. Apparatus as recited in claim 1 including means on said drill string above said packer adapted to control circulation of fluid down said drill string and up the annulus between said drill string and said borehole wall above said packer when said packer is inflated.

7. Apparatus as recited in claim 6 in which said fluid control means comprises:

first passageway means adapted to fluidly communicate the interior of said drill string and the interior of said packer;

first fluid pressure-operated valve means arranged in said first passageway;

second passageway means adapted to fluidly communicate the exterior of said drill string and the interior of said packer connected to said first passageway means; and

second fluid pressure-operated valve means arranged in said second passageway.

8. Apparatus as recited in claim 7 in which said first valve means includes means adapted to maintain said first passageway means open when fluid pressure acting on said first valve means is at a first predetermined pressure level and to maintain said first passageway means closed when said fluid pressure is below said first predetermined pressure level;

said second valve means includes means adapted to open said second fluid passageway means in response to fluid pressure of a second predetermined pressure level higher than said first predetermined pressure level.

9. Apparatus as recited in claim 8 in which said first valve means includes an additional fluid pressure-operated valve means adapted to open said first passageway means in response to fluid pressure between said first and second predetermined pressure levels.

10. Apparatus as recited in claim 6 in which said fluid control means includes a chamber adapted to contain packer inflate fluid; and

piston means arranged on the lower end of said drill string forming the upper end of said chamber adapted to move vertically relative to said tubular member; said tubular member and said drill string being connected together in a manner such that when said drill string is placed in compression, inflate fluid contained in said chamber is forced by said piston into said packer to inflate said packer and seal ofi? the annulus between said tubular member and the borehole wall and when said drill string is placed in tension, said packer is permitted to deflate and force said inflate fluid into said chamber.

11. Apparatus as recited in claim 6 in which said control means on said drill string above said packer comprises:

a circulation port positioned adjacent the lower end of said drill string; and

valve means adapted to open and close said circulation port.

12. A method for controlling formation conditions in a borehole having a drill string with a fully open bore therethrough and with a drill bit on the lower end thereof positioned therein which comprises the steps of:

sealing off the annulus between said drill string and the borehole wall while maintaining said bore through said drill string fully open;

opening a circulation port in said drill string above said sealed-oil annulus; and

circulating fluid down said drill string through said circulation port and up the annulus between said drill string and the borehole wall.

13. A method as recited in claim 12 in which said circulation of fluid is halted;

said circulation port is closed; and

the annulus between the drill string and the borehole wall is unsealed to permit circulation of fluid through the previously sealed-off portion of said annulus.

14. A method as recited in claim 13 in which the annulus between said drill string and the borehole wall is sealed adjacent the lower end of said drill string.

15. The method of controlling formation conditions in a well hole having a drill string with a drill bit on the lower end thereof positioned therein and which is adapted for circulation of a drilling fluid therethrough comprising the steps of:

closing ofl? the annulus between the drill string and the well hole wall at a position spaced above the drill bit while maintaining a fully open bore through said drill string;

circulating drilling fluid through the drill string bore and the annulus through a bypass point spaced above the annulus close-0E position; and

subsequently opening the annulus and resuming the flow of drilling fluid through the drill bit at the bottom of the drill string.

References Cited UNITED STATES PATENTS 2,082,111 6/1937 Layne -321 2,637,401 4/1953 Ramsey 166184 3,044,553 7/1962 Bradley 166184 3,151,690 10/1964 Grable 175321 3,236,307 2/1966 Brown 166-184 3,322,215 4/ 1967 Warrington 175-72 FOREIGN PATENTS 167,198 9/ 1961 U.S.S.R.

JAMES A. LEPPINK, Primary Examiner.

US. Cl. X.R 

12. A METHOD FOR CONTROLLING FORMATION CONDITIONS IN A BOREHOLE HAVING A DRILL STRING WITH A FULLY OPEN BORE THERETHROUGH AND WITH A DRILL BIT ON THE LOWER END THEREOF POSITIONED THEREIN WHICH COMPRISES THE STEPS OF: SEALING OFF THE ANNULUS BETWEEN SAID DRILL STRING AND THE BOREHOLE WALL WHILE MAINTAINING SAID BORE THROUGH SAID DRILL STRING FULLY OPEN; OPENING A CIRCULATION PORT IN SAID DRILL STRING ABOVE SAID SEALED-OFF ANNULUS; AND CIRCULATING FLUID DOWN SAID DRILL STRING THROUGH SAID CIRCULATION PORT AND UP THE ANNULUS BETWEEN SAID DRILL STRING AND THE BOREHOLE WALL. 